ANSI Color support

[bitprophet]

Description

• Easy ability for both internal code and users to specify that (at least) full lines are a given ANSI color, if not words or arbitrary parts of output strings.
• Global flag for disabling ANSI so that anyone who cares can turn it off (e.g. for someone scripting Fab itself, or whatever.)
• Have various internal output calls make use of color so that e.g. "executing task X" lines are blue, running lines are...uh...yellow? green?, aborts/errors are red, and etc etc etc.

Be nice to leverage an external library for this instead of reinventing the wheel for the actual mechanics -- see what's out there.

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ok, there is a handful of prior art:

• Django termcolors.py
• colorize.py
• console.py
• colorama - Kr recommended
• Clint - not sure if Kr is using colorama in this but it does do color =) see also Consider integrating Clint or other external CLI lib #363
• Fabulous
• Blessings

General ideas:

• Unary functions. print(red(blink("text") + "non blinking text")) etc. Seems easy enough to use, possibly some tricky spots in actual implementation -- check Term::ANSIColor (source) for ideas, maybe.
• Dead simple mapping of the codes to constants/vars. (Possibly why nobody's done a lib for this -- it's dead simple.) E.g. print(RED + BLINK + "text" + CLEAR + RED + "non blinking text" + CLEAR).

ANSI code maps:

• Pueblo MUD client list
• Another list from a Ruby implementation
• Wikipedia

More notes:

• there are apparently issues with this on Windows terminals, so may want/need an automatic if win32: env.disable_colors = True sort of thing.
• have regular expressions that can trigger certain highlights, so that e.g. stdout/stderr matching "error messages" can be colored red or whatnot. I.e. "Permission denied" and the like. (see also: capistrano-colors)
• if/when we do logging (Support full logging to file #57) it may make sense to turn colors off for the logs -- or make it an option in case anybody actually wants the ANSI codes in their log files.

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Current status:

• Implemented a barebones in-house lib as fabric.colors in Fabric 0.9.2
• Not using it anywhere in Fabric core yet; only place I use it myself is in one seldom used task
• May still be worth using a 3rd party lib if/when we get around to seriously leveraging color in Fabric itself
  • However, unless a bridge is provided to the current included colors module, doing so is likely to break backwards compatibility
  • So either write such a bridge, don't bother using a 3rd party lib, or wait to do so till 2.x

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Originally submitted by Jeff Forcier (bitprophet) on 2009-11-11 at 05:46pm EST

Relations

• Related to Make fabfile print() statements controllable via output controls #151: Make fabfile print() statements controllable via output controls
• Related to Use background colors in fabric.colors #240: Use background colors in fabric.colors
• Related to Support full logging to file #57: Support full logging to file
• Related to Consider integrating Clint or other external CLI lib #363: Consider integrating Clint

[bitprophet]

Jeff Forcier (bitprophet) posted:

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Started playing around with this. One possible color scheme, using magenta hostnames, green tasks and blue running lines:

(You can ignore the actual text, it's just duplicated output from a real task run. No, the domains involved can't be accessed publicly :))

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on 2009-11-12 at 02:10pm EST

[bitprophet]

Jeff Forcier (bitprophet) posted:

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Another example, with additions:

• yellow for stderr
• red for abort messages (probably also warnings.)

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on 2009-11-12 at 02:34pm EST

[bitprophet]

Jeff Forcier (bitprophet) posted:

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Also, I've never said I don't use stupid crap as test messages :) no offense to anybody's mother.

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on 2009-11-12 at 02:35pm EST

[bitprophet]

Nick Trew (vxnick) posted:

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Consider adding env.always_use_bold (or similar).

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on 2010-04-14 at 10:06am EDT

[bitprophet]

Kenneth Reitz (kennethreitz) posted:

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I highly recommend colorama:

http://pypi.python.org/pypi/colorama

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on 2010-10-11 at 10:49pm EDT

[bitprophet]

Rick Harding (mitechie) posted:

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Kenneth Reitz wrote:

I highly recommend colorama:

http://pypi.python.org/pypi/colorama

+1 on colorama, very nice and easy to wrap so you make it optional. If colorama is installed you can output with colors, else plain.

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on 2011-03-14 at 11:25am EDT

[turicas]

fabulous is a great library to work with colors in Python! I don't know colorama, but if we only need 8-bit colors, I can do a function to do it with just 20 lines of code (and will not depend on another library). But if we need more complete support, I think fabulous will be a great choice.

[bitprophet]

FWIW I am currently a huge proponent of 256-color terminals :) I will add fabulous to the list up top, thx!

[andelf]

my custom color function.

def colorize(msg, fg='green', bg='black', style='reset'):
    color_map = dict(black=0, red=1, green=2, yellow=3, blue=4, magenta=5, cyan=6, white=7)
    style_map = dict(reset=0, bold=1, underscore=4, blink=5, reverse=7, conceal=8, underline=4)
    return '\033[3%d;4%d;%dm%s\033[0m' % (color_map[fg], color_map[bg], style_map[style], msg)

[bitprophet]

#554 includes a screenshot and possibly some code, to be considered alongside the above.